The Immunohistopathology Core (Core C) will provide coordinated and efficient facilities to allow reproducible and predictable histochemical processing of tissue samples that will be subsequently analyzed by automated or semi-automated image analysis techniques. Dr. Stokes and Popovich as CO-PI's will supervise a team that has an established record in dealing with the quantitative aspects of tissue morphometrics, cell counting, immunohistopathology, in situ hybridization, gel analysis and autoradiography. Accuracy and reproducible outcomes are therefore likely to result from such an approach. We will provide oversight responsibilities for the facility including scheduling, training of project personnel in histological preparation/analysis and supervise use of the imaging/microscopic facilities as necessary. The enhanced system (Zeiss Axioplan light microscope together with microcomputer imaging software of an MCID 4 system will capacities for darkfield and differential interference contrast (DIC) optics, epi-fluorescence illumination for immunohistochemistry/immunofluorescence and software that facilitates semi-automated cell counts, cell morphometric analysis, and the ability to do fractional densitometric analysis of tissue areas) that will be used in this proposal is unique in that it replaces a variety of less sensitive, cumbersome technologies that have previously been used for this purpose by individual project investigators. Technical personnel in the facility will also be well versed in the employment of the hardware and software proposed in the imaging center, particularly as it applies to immunocytopathology, densitometry, and fluorescent techniques. An additional technician requested in the present proposal will provide support to projects 2-4 involving: (1) methods of fixation, (2) planning and execution of tissue sectioning, (3) appropriate immunohistochemical techniques, and (4) data analysis/management (e.g., stereological techniques, sampling methods, etc.) data storage/cataloging, and data presentation. This technical approach will be aided in data analysis and statistical procedures by a close working relationship between this Core and Core B (Statistical Core). Core B will advise on appropriate database technology or need for convertible modes of data presentation and/or new software for quantitative stereological procedures.